Spiro[bicyclo[4.1.0]heptane-2,5′-[1,3]dioxane], 2′,2′,3,7,7-pentamethyl-, (1.alpha.,3.beta.,6.alpha.)- (CAS 121251-68-1) — Woody Base Note Fragrance Ingredient
Spiro[bicyclo[4.1.0]heptane-2,5'-[1,3]dioxane], 2',2',3,7,7-pentamethyl-, (1.alpha.,3.beta.,6.alpha.)-
CAS 121251-68-1
What Is Spiro[bicyclo[4.1.0]heptane-2,5'-[1,3]dioxane], 2',2',3,7,7-pentamethyl-, (1.alpha.,3.beta.,6.alpha.)-?
This synthetic fragrance compound is primarily encountered in professional perfumery as a specialty ingredient. Its complex structure makes it valuable for creating unique olfactory effects in modern fragrance compositions. While not commonly recognized by consumers directly, it contributes to the depth and longevity of certain luxury perfumes. The ingredient matters to perfumers seeking novel woody-amber nuances that can’t be achieved with traditional materials. Its stability and diffusive properties make it particularly useful for creating signature accords in contemporary fragrances.
Safety Profile
USE WITH AWARENESSWhat Does Spiro[bicyclo[4.1.0]heptane-2,5'-[1,3]dioxane], 2',2',3,7,7-pentamethyl-, (1.alpha.,3.beta.,6.alpha.)- Smell Like?
The aroma profile presents a sophisticated interplay of woody and ambery characteristics with subtle spicy undertones. Initially, it reveals a crisp, almost camphoraceous top note that quickly transitions into a warm heart of smooth sandalwood-like richness. The dry-down evolves into a complex base reminiscent of aged cedar chests with a whisper of vanilla-like sweetness. Throughout its evolution, it maintains an intriguing mineralic quality that adds modern freshness to traditional woody accords. The diffusion is moderate but persistent, making it particularly valuable for creating dimensional base notes with surprising lift.
2D Molecular Structure
SMILES: C[C@@H]1CC[C@H]2[C@H](C2(C)C)C11COC(C)(C)OC1
Chemistry, Properties & Perfumer Guide
The Chemistry
This compound belongs to the spirocyclic ether class, characterized by its unique bridged ring system connecting a bicycloheptane core with a dioxane moiety. The pentamethyl substitution pattern contributes to its stability and olfactory properties. Synthesis typically involves multi-step routes starting from terpene precursors, with key steps including cyclization and methylation. The specific stereochemistry (1α,3β,6α) is crucial for its odor profile, demonstrating how subtle structural variations can dramatically impact fragrance performance. Its relatively large molecular size contributes to its persistence in fragrance formulations.
Physical & Chemical Properties
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Base note modifier |
| Functional Fragrance | 0.1-0.5% | Up to 1% | Longevity booster |
Classic Accords
Tip: Use in trace amounts to add sophistication to woody-amber bases without overwhelming the composition.
Alternatives & Comparisons
Offers similar woody-diffusive properties but with more pronounced dry wood character and higher impact at lower concentrations.
Provides comparable amber-woody depth but with less spicy nuance and more marine facets.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA standards. General usage guidelines for fragrance materials apply.
RIFM Assessment
Under review by RIFM. Preliminary data suggests typical usage levels pose minimal risk.
Sustainability
As a synthetic material, this compound avoids natural resource depletion concerns but requires energy-intensive synthesis. The production process should follow green chemistry principles to minimize environmental impact. Being highly potent at low concentrations contributes to its sustainability profile by reducing the quantity needed in formulations compared to less powerful alternatives.
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Ingredient Data Sheet
CAS 121251-68-1Physical Properties
| Molecular Weight | 238.37 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 3.7🔬 PubChem |
| Boiling Point | 263 °C🔬 EPA CompTox |
| Vapor Pressure | 0.0003 mmHg @ 25°C📊 OPERA |
| Flash Point | 92.7 °C🔬 EPA CompTox |
| log Kp (skin permeability) | -1.527💻 Calculated |
| SMILES | CC1CCC2C(C2(C)C)C13COC(OC3)(C)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Base💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 7.5 / 5💻 Calculated |
Odor & Flavor
| Functional Groups | ether💻 RDKit |
Physical data: PubChem (NIH/NLM), U.S. EPA CompTox Dashboard, EPA OPERA models, RDKit. Odor & flavor: Arctander (Perfume & Flavor Chemicals), Fenaroli's Handbook of Flavor Ingredients, Leffingwell. Thresholds: van Gemert (Compilations of Odour Threshold Values). Regulatory: IFRA Standards 51st, FEMA GRAS. Trade names: Surburg (Common Fragrance & Flavor Materials). All data compiled and cross-referenced for perfumertools.com.
Physicochemical Properties
DTXSID: DTXSID70888256
Physical Properties
| Molecular Weight | 238.371 g/mol🔬 EPA CompTox |
| Density | 1.015 g/cm^3📊 OPERA |
| Boiling Point | 252.71 °C📊 OPERA |
| Melting Point | 58.293 °C📊 OPERA |
| Flash Point | 103.151 °C📊 OPERA |
| Refractive Index | 1.497 Dimensionless📊 OPERA |
| Molar Volume | 235.189 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.006 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 4.006 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.006 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 7.07 Log10 unitless📊 OPERA |
| Water Solubility | 0.001 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.019 mmHg📊 OPERA |
| Surface Tension | 32.508 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 18.46 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 0 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 68.808 cm^3/mol📊 OPERA |
| Polarizability | 27.278 Å^3📊 OPERA |
Data Sources:
🔬 EPA Experimental data from U.S. EPA CompTox Chemicals Dashboard & CTX APIs. 📊 OPERA Predicted using EPA's OPERA QSAR models. 💻 Computed Calculated from SMILES using RDKit.
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